Long-standing tensions over North Korea's nuclear programme worsened when it tested two intercontinental ballistic missiles in July. That prompted a new round of UN economic sanctions, which angered Mr Kim's regime.

Mr Trump said the US military was "locked and loaded", while Pyongyang has accused him of "driving" the Korean peninsula to the "brink of a nuclear war".

But Mr Pompeo denied that a threat of a nuclear conflict was imminent, saying: "I've heard folks talking about being on the cusp of a nuclear war. I've seen no intelligence that would indicate that we're in that place today."

Several countries have expressed concern with the escalation of the crisis. China, North Korea's only major ally, has urged restraint.

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Media captionIt's not the first time North Korea has made threats against Guam

North Korea announced on Thursday plans to fire missiles near the US Pacific territory of Guam, even though there was no indication an attack is imminent.

In response, Mr Trump said North Korea should expect "big, big trouble" if anything happened to Guam.